Sparkpost SMTP not playing nice

Hi guys, kudos on the plugin and the service. I was a long time user of Mailpoet2 and have always thought of you as the newsletter solution.
I have recently moved to Mailpoet3 and am having issues with setting up the Sparkpost smtp. I have everything setup on the Sparkpost side of things and these are the setting they suggest
Host smtp.sparkpostmail.com
Port 587
Alternative Port 2525
Authentication AUTH LOGIN
Encryption STARTTLS
Username SMTP_Injection
and pwd
This is what is going into my settings and per this article, I have an email address [email protected] as the “from” since that is the sending URL I set up on Sparkpost. FYI [email protected] doesn’t exist
Any help would be greatly appreciated, Thanks !